I have bee baking my own sour-bead for many years and it has been a long learning process discovering not only the process of fermentation, also the many uses in bread, cakes (like Panettone) and pizza making.
My interest in sourdough started because I wanted to reproduce the same flavor of the Italian food, in particular, the bread from Tolfa (near Rome), my mother’s birthplace.
While researching I not only found original recipes and uses, I also discovered the many health benefits of natural fermentation.
Sourdough it has been made for thousands of years old is very simple to make, it’s a mixture of ground cereals and water that ferments spontaneously. Sourdoughs improve the properties of the bread dough, enhance bread texture and flavor, and delay bread spoilage and staling.
To start your sourdough, you create the “starter” by combining water and flour in a glass jar and cover it with a cotton cloth, leave at room temperature for few hours until the fermentation occurs, and you see air bubbles in the mixture.
To use the starter, add more water and flour and let it ferment for few hours for the dough to double in size. Most of the dough can be used to make the bread, leaving a little bit back as the starter for the new batch of bread.
You can keep the starter undisturbed in the fridge for days, weeks or months between bakes.
Time is the characteristic of sourdough, during the slow fermentation the enzymes digest the sugar content in grains and reduce phytates (and Phytic acid) by up to 90% which are linked to digestive problems, often linked with IBS.
Phytic acid (Phosphorous) contained in the wheat, is often considered an anti-nutrient because it binds minerals in the digestive tract, making them less available to our bodies, and inhibits enzymes needed for the digestion of proteins.
The wild yeast and lactobacillus in sourdough, neutralize the phytic acid and its negative effects. As the dough acidifies effectively pre-digests the flour, releases the micronutrients, increase magnesium and phosphorus solubility, and in turn reduces bloating and digestive discomfort.
What’s more, it is believed that the probiotic in the sourdough bread improve gut health even though it is cooked.
Sourdough is naturally low in sugar, that’s because the enzymes feed on sugar during the process of fermentation. Sourdough bread also takes longer to digest and doesn’t tend to cause the same spike in blood glucose levels as other bread can, helping ward off diabetes.
Terry Graham, a professor in human health and nutritional sciences at the University of Guelph, Ontario lead a team of researchers who studied four types of bread to determine which had the most positive health effects when it comes to carbohydrate metabolism, blood sugar, and insulin levels.
The results were impressive. The white bread and whole wheat bread showed very similar responses, an initial spike followed by declining levels despite the general belief that whole wheat bread could be healthier. The white sourdough bread showed the least pronounced response, with both blood glucose and insulin increases significantly lower than those seen following a breakfast of non-sourdough bread.
Following their first study, the team looked at other hormonal responses and included other bread in their trials. The results consistently showed sourdough to be associated with more moderate blood sugar response. Whole grain sourdough bread was found to show a similar response to white, while a sprouted grain sourdough showed the most positive response.
Terry realized that fermented foods from a range of cultures have been associated with good health.
A recent study by Adele Costabile and her team of researchers from the University of Reading investigated the effects that bread with different fermentation times had on the gut and found that for some IBS sufferers, bread may still be on the menu.
From the study: “More specifically, a change in bread making processes from a traditional long fermentation process to a short, incomplete fermentation may have contributed to bread intolerance through its effects on fermentation in the colon.”
Industrially manufactured, processed bread relies on enzymes, preservatives, emulsifiers, and chemicals to bake bread at speed. These additives are also to blame for some people’s wheat intolerance.
There is no regulation that states what can be called sourdough. Most sourdough sold in shops are made from yeasted bread with added sourdough powder or in liquid form to give the taste of a sourdough, hence it can still be made in around on hour. This bread will not have the benefit of a ‘real’ sourdough bread.
Here’s a summary of the many benefits of sourdough, as revealed by research done in the past fifteen years (by Andrew Whitley).
- Sourdough can modify the bits of gliadin and glutenin protein in wheat flour that are toxic to people with coeliac disease (CD) and non-coeliac gluten sensitivity.
- LAB (including those commonly found in sourdough bread) produce beneficial compounds: antioxidants, the cancer-preventive peptide lunasin, and anti-allergenic substances, some of which may help in the treatment of auto-immune diseases. Interestingly, these by-products seem able to survive heating, suggesting that baked sourdough bread may have ‘probiotic’ potential by stimulating immune responses in the gut.
- Bread, especially if made with unrefined flour, is a significant source of dietary minerals such as iron, calcium, magnesium, and zinc. But a slice of fast-made wholemeal may be nutritious only in theory if its contents pass straight through the body without being absorbed. The main culprit here is phytic acid, present in the bran layers of cereals, which ‘locks up’ the important minerals. Several hours of fermentation with sourdough is sufficient to neutralize phytic acid and make the minerals more bioavailable.
- Problematic protein fragments are not the only thing in bread that we might want to reduce to a minimum. Acrylamide, a suspected carcinogen, can be found in bread crusts. Long fermentation, typical of sourdough systems, can reduce levels of the amino acid asparagine that is a precursor of acrylamide formation.
- Bread is often avoided by those affected by weight-gain and metabolic syndrome – rightly, perhaps, in the case of industrial white loaves with a high glycaemic index (GI). But sourdough produces organic acids that, under the heat of baking, cause interactions that reduce starch availability. The lowest GI bread are whole-grain sourdoughs with a compact texture.